Yeah, I would shop around. I have seen prices vary but for someone who knows what they are doing it shouldnt take as long as someone who has never installed coils on a M3.

Some places go by the book and usually do it faster if they know what they are doing.

To get the coils installed, dialled, and alignment it should cost more than $400 from my experiences but shops do vary in price and maybe someone from the forum could reference you which would be your best bet. I would say $300 is a deal but only from a shop who has done this install many times and not a shop that just needs to make money and will play around to get it done.

That price is nearly double what we would charge for the same work at our facility, but a number of factors are at play here:

Hourly rate- The shop's hourly rate is dictated by such things as land value (which translates to cost of building ownership), local tax rates, local market rates, etc... A shop in Oklahoma may charge a very different labor rate than the same quality of shop located in downtown Chicago.

Hours quoted- Various shops bill very differently. If the shop is charging "book time" for the job, they might be billing you at 8-10 hours for the suspension install. If the shop is charging you "actual time", they might bill you for only 4-5 hours.

Alignment- Is the shop performing an alignment, and including that in the price? Some shops account for 2-3 hours for a proper alignment, so this may be a factor as well.

If the shop is including an alignment in their bill, they might be accounting for 6-7 hours of total work, putting their labor rate at $100~$110 per hour. This might be in line with what other good shops in the area are charging, or it may be far higher. That's the trick to finding the answer to your question. You might ask your shop what their hourly rate is, how many hours they plan on spending on your work, and whether or not they are including an alignment, to help you get a more clear picture.